04 First Flight

by: Jan Zumwalt

About the author - Jan Zumwalt, earned his Aeronautical engineer degree from the University of Alaska - Anchorage. Jan has over 2000hrs as pilot in command and has been employed as maintenance supervisor for several small commuter flight services. He also served as shift maintenance supervisor for Continental Airlines. He has designed and assisted many successful kit aircraft.

First Flight

The first flight has three primary goals.

So it is time to go ....
Check once more your center of gravity at mid-range position from the full travel given by the designer. Check your fuel quantity, check it physically with your eyes or a dipstick, do not rely on the fuel gauge until proven reliable.

Okay, the aircraft is ready, but how about you?
First of all, you must want to do that first flight - do not let anyone push you into the air, even if he/she is a well-meaning relative or friend. Second, you must be relaxed - you may check your astrological sign or biorhythms if you want - but the important thing is you simply feel this is the day! And definitely not with the help of a couple of beers!

Now, check the weather: There should be little or no wind, good visibility (no haze) and at least a 3,000 foot ceiling. Avoid the time around sunset if your active runway is 22 to 33! And, have as few friends around as possible. (They have a tendency to make us show off; we can do that later. Now, we just want to get up, gather important information, and come down again as safely as possible, and get a good feel of that beauty sitting out there waiting.)

I have found that the best time for smooth weather is when those so-called friends are still in bed, when only the one reliable friend you really want around shows up. This best time is approximately one hour after sunrise.

Proceed with your pre-flight - fuel check, drain fuel system for condensation, water. Then, start the engine, warm it up and taxi to the take off end, check ignition and carburetor heat. Set the altimeter and trim at mid travel. If you wish, check full throttle rpm (I usually do this during the initial phase of take off).

Line up with the runway and push the throttle full open, not too slowly but not too quickly either. Keep one eye on the air speed, the other on the runway and one ear to the engine; if anything seems abnormal, just shut the craft down, check it and fix it. In our lives we get many warnings. We should listen to them and not have a "stubborn ego." And, I repeat, checking is not enough. If something is wrong, we have to fix it and then try again! But, today, everything is fine, so we keep the throttle open and very slowly lift the airplane off as soon as you think you are fast enough. Be prepared, it may be very nose heavy or light; we do not know the trim position yet.

Now that you are in the air, remember the danger is to hit mother earth again before you want to, so climb gently at some 10/20 mph faster than your lift-off speed. Adjust the trim for comfort, check the rpm, airspeed, engine, instruments (if it starts overheating, throttle back a little) . . . and relax! Not too much, though - keep one eye on the airport to which you want to return.

At two or three thousand feet AGL, still full throttle, level off. Push the nose slightly down until altitude no longer increases, note the rpm (this should be less than 110 percent of the red line). Is there any unusual noise or vibration you should note?

Now, throttle back to about 90 percent of above full throttle rpm (this should be approximately 75 percent of cruise) and trim for level flight.

Finding the Stall Speed

Before you land you must know the indicated speed at which the aircraft will stop flying, so you better find out now when you are up high.

Relax! Carburetor heat on, throttle gently back (notice the tendency of the nose), now slowly raise the nose to reduce the speed. Do not use ailerons, keep the ball centered - or the wings level with your rudder. Do everything gently and stay relaxed. Keep one eye on the air speed and the other on the ball (or horizon and wing tips). Notice everything: buffeting, stick back pressure, control stops, "oil canning" or other noises....

Any well designed and correctly built light plane should have a gentle stall; its nose will gently (more or less!) drop. One wing may drop faster than the other (slight asymmetry in wing construction, or too little use of the rudder, or gusty weather). Notice the indicated stall speed then release the stick pressure slowly to increase the airspeed and reattach the air flow over the wing. Apply full power gently and climb at 130 percent of your stall speed. Trim (this trim setting will be your take off trim in this configuration, weight, C.G. and flaps up).

Check the airport (or are you lost by now?)
Make another two or three stalls to get a good average reading and feel comfortable.

Now come in for a landing: Use 130 percent of stall speed on base and final, aim a few feet above the runway entrance and reduce throttle, then speed only over the runway and just hold her back until the aircraft settles by itself on the ground at the stall speed you now know (do not "pump" her down!)

Without stopping the engine, taxi back for another take off. This time set the trim for climb, make the take off rotation at the indicated stall speed, accelerate to 130 percent of stall and let her climb, downwind at "cruise," base and final at 130 percent stall as for the first landing.

Perform one or two more circuits before you bring her back to her tie down. Correctly done, the above exercises will take 45 to 60 minutes. And now you are no longer afraid of your aircraft: You know it flies and you can handle it! Your aircraft was designed and built to fly and it does.

Call the designer of your aircraft and share with him the pleasure of your first flight - both you as the builder and he as the designer deserve it.

Next time you fly, start using flaps (if applicable).

Next month we will talk some more about the testing that should be completed during those first 15 hours of flying your new light plane.